Bacteriological Analysis Of Faecal Pollution And Solar Radiation Disinfection Of Domestic Water Sources Within Lake Naivasha Basin, Kenya

ABSTRACT

There is an increase in exposure of water sources to faecal contamination as a result of expanding anthrogenic activities in Lake Naivasha basin in Kenya. This contamination exposes water users in the region to a variety of health risks. This study investigated faecal pollution of community water sources (lake, rivers and boreholes) within Lake Naivasha basin through determination of the concentrations of total coliforms, Escherichia coli, intestinal enterococci, Clostridium perfringens and heterotrophic bacteria in various water sources using Membrane Filtration Technique (MFT) and Heterotrophic Plate Count (HPC) procedures. The potential of solar pasteurization in disinfecting domestic water was also explored by heating known volumes of water samples in a black solar box cooker at given time intervals. In addition, determination of E. coli to intestinal enterococci ratio was used in faecal pollution source tracking. Physicochemical parameters were measured in situ for all water sources. Data was analysed for mean variation using Statistical Package for Social Sciences (SPSS) version 17 software. Surface water sources gave higher values for all microbiological parameters than borehole sources. Borehole direct sources showed no significant variation for all microbial parameters (E. coli, total coliform, intestinal enterococci, C. perfringens and HPC) with respect to sampling sites, the same was also observed in borehole at the Points of Access (POA). Surface water sources on the other hand, showed significant spatial variation for all microbial parameters (P